In a testy interview Mr Corbyn also did not guarantee he would push the so-called "nuclear button" to launch a pre-emptive strike.

And he did not guarantee he would authorise a strike to kill ISIS' leader, instead saying any killing must support a "political solution".

Pressed on whether killing ISIS's leader would help that solution, Mr Corbyn said: "I think the leader of ISIS not being around would be helpful and I'm no supporter or defender in any way whatsoever of ISIS."

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Asked if backing for Trident will be in the 2017 manifesto, as said by Mr Corbyn's own Defence Secretary, the Labour leader said: "We haven’t completed work on the manifesto yet, as you’d expect. We’re less than 100 hours into this election campaign.

A Labour spokesman said after the interview: "The decision to renew Trident has been taken and Labour supports that. We also want Britain to do much more to pursue a proactive, multilateral disarmament strategy.

"Let’s be clear that it is the Tories’ spending cuts and broken promises on defence that are putting Britain’s security at risk. Under them the Army has shrunk to its smallest size since the Napoleonic Wars. Despite the Tories’ pledge before 2010 of "a bigger army for a safer Britain," they slashed the army from 102,000 in 2010 to 80,000 in 2016, breaking a manifesto commitment to keep it at 82,000.

"Knee-jerk decisions since 2010, like scrapping Nimrod, HMS Ark Royal and the Harrier jump jets, have weakened our defences and cost British taxpayers millions. The Air Force has been forced to rely on allies to track Russian subs off the UK coast, while the size of the Navy’s fleet of frigates and destroyers has fallen to just 19.

"These kinds of cheap attacks simply show they're desperate to avoid scrutiny of their own record of failure."